The second daily flight would be welcome not only for connections but also for visitors to the UAE.
Arriving around midnight is not ideal when hotels in that part of the world are so expensive. You will end up paying potentially upwards of £200 for a "wasted" hotel night. Much better to fly overnight and arrive early in the morning and make the most of a mini break in the gulf. I have flown BA via LHR to DXB twice in the last couple of years as flight times have been better (and much cheaper) then direct from NCL.